<!DOCTYPE html>
<html lang="en">
  <head>
        
    <meta charset="UTF-8" />
        
    <style>
      a[class~="baidu"]:link {
        color: aquamarine;
        border: 5px solid red;
      }
      a[class~="baidu"]:visited {
        color: rgb(205, 26, 221);
        border: 5px solid blue;
      }
      a[class~="baidu"]:hover {
        color: aqua;
        border: 5px solid gray;
      }
      a[class~="baidu"]:active {
        color: brown;
        border: 5px solid purple;
      }
    </style>
  </head>

  <body>
      <a href="" class="hello baidu">这是一段文字超链接</a>
      <hr />
      <a href="" class="">这是一段文字超链接</a>
      <a href="http://www.baidu.com">hello</a>
    <hr />
  </body>
</html>
